JP2019189664A - Production method and production apparatus of cellulose nanofibers - Google Patents

Abstract

To provide a production method and a production apparatus of cellulose nanofibers with foreign matter removed as much as possible because magnetic materials or foreign matter containing magnetic materials, if mixed when producing cellulose nanofibers, cause hindrance to operation of a fibrillation apparatus and the like.SOLUTION: A raw material slurry S is circulated via a return pipe 10 by operation of a circulation pump 3 while stirring the inside of a raw material tank 2 by a stirring device 8. Magnetic body adsorption means 4a and 4b are placed on a return pipe 10 to capture by adsorption magnetic bodies and foreign matter containing magnetic bodies in the raw material slurry S. After a desired time has passed, the raw material slurry 2 is supplied to a fibrillation step 13. The magnetic body adsorption means 4a and 4b are removed from the return pipe 10 and cleaned to remove magnetic bodies or foreign matter containing magnetic bodies captured by adsorption and, thereafter, installed again on the return pipe 10.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method and an apparatus for producing cellulose nanofibers.

  Nanofibers, so-called nanofibers, have been attracting a great deal of attention by making the fibers as thin as possible. Among these types of nanofibers, cellulose nanofibers are derived from plant fibers produced from wood fibers, so they are renewable resources and have a low environmental impact on production and disposal. Has been.

  Cellulose nanofiber is a fiber having a nano-level fiber diameter of 1000 nm or less, and its dispersion has high transparency. For this reason, application to transparency, for example, optical film, film coating agent, compounding to glass and the like is expected.

  This cellulose nanofiber can be generally obtained by defibrating chemically modified cellulose fiber with mechanical shearing force (see Patent Document 1). In addition, regarding the manufacturing method of a cellulose nanofiber, various manufacturing methods including the manufacturing method described in patent document 1 are examined.

  Cellulose fibers are made from natural cellulose isolated from softwood and hardwood wood pulp, cotton pulp, non-wood pulp such as straw pulp, etc., and oxidized to obtain reactant fibers and impurities. It is obtained by a purification step for obtaining a reaction product fiber that has been removed and impregnated with water, and a dispersion step for dispersing the water-containing reaction product fiber in a solvent. Moreover, it is preferable that the natural cellulose used as a raw material is generally available, and since it is generally available, there is a possibility that various impurities are contained. In Patent Document 1, a dispersion of high-purity reactant fibers and water is obtained by repeating water washing and filtration using an apparatus such as a strainer in the purification step.

  Further, Patent Document 2 proposes a papermaking chest provided with a feeding portion having a foreign matter removing function for removing foreign matters mixed in raw materials, fillers or paper stock in the paper manufacturing process. .

JP 2008-1728 A JP 2006-132848 A

  However, when impurities or other foreign matters are mixed, the quality of the product is lowered. There is a risk of operation stoppage due to clogging or damage to the device. Even in the case of the filtration described above, the opening of the strainer cannot be a size that allows the pulp fiber to pass through. If the opening has a size that does not allow the pulp fiber to pass, the opening of the strainer is affected. It becomes impossible to remove a magnetic substance having a particle size or a foreign substance containing the magnetic substance.

  In addition, it is inconvenient to divert the method for removing foreign matters in the papermaking process for treating fibers in millimeters to a process for producing cellulose nanofibers that require treatment of nano-order fibers, which is disclosed in Patent Document 2. In addition, it is inevitable that foreign matters are mixed in the cellulose nanofibers manufactured by the apparatus having a foreign matter removing function.

  Therefore, the present invention provides a method and apparatus for producing cellulose nanofiber that removes as much as possible even a fine magnetic substance or a foreign substance containing a magnetic substance so that the operation of the defibrating apparatus is not affected. The purpose is to do.

  As a technical means for achieving the above-mentioned object, a method for producing cellulose nanofibers according to the present invention includes a cellulose fiber dispersion in which fine cellulose fibers are dispersed in a desired solvent using natural cellulose as a raw material. In the method for producing cellulose nanofibers, the inside of the raw material tank in which the raw material slurry of cellulose nanofibers is stirred is stirred by a stirrer, and the raw material slurry discharged from the raw material tank is circulated by a circulation pump connected to the raw material tank. It is returned to the raw material tank through a return pipe connected to the discharge side of the pump, the raw material slurry is circulated between the circulation pump and the raw material tank, and a magnetic substance adsorbing means having a magnet is arranged in the return pipe. Thus, the magnetic material or the foreign matter containing the magnetic material mixed in the raw material slurry is adsorbed, and the raw material slurry is circulated. After circulating at a desired time between the flop and the raw material tank, it is characterized by supplying the raw slurry to the next step.

  Further, when carrying out this manufacturing method, it is possible to branch the supply pipe by providing a branch part in the middle of the return pipe, and supply the raw slurry to the next step through the supply pipe after circulation for a desired time.

  Moreover, it is preferable to arrange a magnetic substance adsorbing means between the circulation pump and the branch part so as to adsorb the magnetic substance or a foreign substance containing the magnetic substance.

  Further, a return-side switching valve is arranged on the return pipe downstream of the branching portion, and a magnetic substance adsorbing means is arranged on the downstream side of the return-side switching valve to adsorb a magnetic substance or a foreign substance containing the magnetic substance. preferable.

  Further, it is preferable that a supply side switching valve is arranged in the supply pipe, and a magnetic substance adsorbing means is arranged downstream of the supply side switching valve to adsorb a magnetic substance or a foreign substance containing the magnetic substance.

  The cellulose nanofiber production apparatus according to the present invention is a cellulose nanofiber production apparatus for obtaining a dispersion of cellulose fibers in which fine cellulose fibers are dispersed in a desired solvent using natural cellulose as a raw material. Raw material slurry circulation including a raw material tank for storing fiber raw material slurry, an agitator for stirring the raw material slurry in the raw material tank, and a circulation pump and a return pipe for discharging the raw material slurry from the raw material tank and returning it to the raw material tank And a magnetic substance adsorbing means having a magnet disposed in the middle of the raw material slurry circulation path, and circulating the raw material slurry between the raw material tank and the circulation pump through the raw material slurry circulation path After adsorbing the magnetic material or foreign material containing the magnetic material by It is characterized by supplying to.

  Moreover, it is preferable to provide a pipeline switching means for switching the supply of the raw material slurry discharged from the circulation pump to one or both of the return pipe and the supply pipe.

  The pipeline switching means may be composed of a return side switching valve arranged in the return pipe downstream of the branching section and a supply side switching valve arranged in the supply pipe.

  Further, the pipe line switching means can be a three-way valve arranged at the branch portion.

  Moreover, it is preferable to arrange the magnetic substance adsorbing means on either one or both of the return pipe and the supply pipe on the downstream side of the pipe switching means.

  According to the method and apparatus for producing cellulose nanofibers according to the present invention, the raw material slurry stored in the raw material tank is circulated through the raw material slurry circulation path while stirring, and a magnetic substance is provided in the middle of the raw material slurry circulation path. Since the adsorbing means is provided, the magnetic substance or the foreign matter containing the magnetic substance mixed in the raw material slurry flowing through the raw material slurry circulation path is adsorbed and captured by the magnetic substance adsorbing means. In addition, since the magnet is attracted, the fibers in the raw slurry are not damaged, and even if the foreign matter contains fine magnetic materials or magnetic materials that cannot be removed by a strainer or the like, regardless of the size of the fibers. be able to.

It is the schematic which shows the structure of the outline of the manufacturing apparatus of the cellulose nanofiber for demonstrating the manufacturing method and manufacturing apparatus of the cellulose nanofiber which concern on this invention. It is a table | surface which shows the effect at the time of implementing the removal of a foreign material with the manufacturing method and manufacturing apparatus of the cellulose nanofiber which concern on this invention.

  Hereinafter, based on a preferred embodiment schematically shown in FIG. 1, a method and an apparatus for producing cellulose nanofiber according to the present invention will be specifically described.

  The cellulose nanofiber production apparatus 1 according to the present invention is mainly composed of a raw material tank 2 for storing the raw material slurry S, a circulation pump 3, magnetic material adsorbing means 4a and 4b, and an agitation device 8 for stirring the inside of the raw material tank 2. Has been. In addition, since it is necessary to supply the raw material slurry S processed with this cellulose nanofiber manufacturing apparatus 1 to the following process, it is preferable to provide the switching valves 5 and 6 and the magnetic body adsorption | suction means 7 as an apparatus for that.

  A raw material slurry S is supplied and stored in the raw material tank 2. The stored raw material slurry S is stirred by the stirring device 8. The stirring device 8 stirs the raw material slurry S by rotating the stirring blade 8a immersed in the raw material slurry S stored in the raw material tank 2 via the rotation shaft 8c of the drive motor 8b. A suction port of the circulation pump 3 is connected to the raw material tank 2 via a suction side pipe 9.

  A return pipe 10 is connected to the discharge port of the circulation pump 3, and an open end 10 a of the return pipe 10 faces the raw material tank 2. Alternatively, the open end 10 a is connected to the raw material tank 2. Therefore, the raw material slurry S stored in the raw material tank 2 is circulated between the raw material tank 2 and the circulation pump 3 so as to be discharged by the circulation pump 3 and returned to the raw material tank through the return pipe 10. It will be. That is, a raw material slurry circulation path is formed by the suction side pipe 9, the circulation pump 3, and the return pipe 10.

  A branch section 11 is provided in the middle of the return pipe 10, and a supply pipe 12 is connected to the branch section 11. Of the switching valves 5 and 6, the return side switching valve 5 is arranged in the return pipe 10 on the downstream side of the branch portion 11, and the supply side switching valve 6 is arranged in the supply pipe 12. In addition, the raw material slurry S is supplied to the next process such as the defibrating process 13 through the supply pipe 12 and is further supplied from the defibrating process 13 to the subsequent process 14.

  The magnetic substance adsorbing means 4 a is a discharge-side magnetic substance adsorbing means 4 a arranged in a return pipe 10 between the discharge port of the circulation pump 3 and the branching portion 11, and the magnetic substance adsorbing means 4 b is a function of the return-side switching valve 5. The return side magnetic body adsorption means 4b arranged on the downstream side is used. In addition, although it is preferable to arrange | position both these magnetic body adsorption | suction means 4a, 4b, you may be any one. The magnetic body adsorbing means 7 is a supply side magnetic body adsorbing means 7 disposed on the downstream side of the supply side switching valve 6.

  These magnetic body adsorbing means 4a, 4b, 7 have a structure in which a permanent magnet is accommodated in a case formed of stainless steel or the like, and the fluid that is arranged inside the pipe and flows in the pipe is the magnetic substance adsorbing means 4a, 4b and 7 are brought into contact with the magnetic substance or the foreign substance containing the magnetic substance mixed in the fluid, and are attracted and captured by the magnet. There are various shapes depending on the nominal diameter of the pipe, and there are rod-shaped and grid-shaped ones. Further, as the material of the case, a material having good wear resistance with respect to the properties of the fluid is used. The magnetic body captured by the magnet or the foreign matter including the magnetic body is adsorbed on the outer surface of the case.

  The operation of the cellulose nanofiber manufacturing apparatus according to the present invention configured as described above will be described, and a cellulose nanofiber manufacturing method using this manufacturing apparatus will be described together.

  The return side switching valve 5 is opened and the supply side switching valve 6 is closed. The raw material slurry 2 stored in the raw material tank 2 is stirred by the rotation of the stirring blade 8 a of the stirring device 8. Further, by the operation of the circulation pump 3, the air is sucked from the suction port through the suction side pipe 9 and discharged from the discharge port to the return pipe 10. When the raw material slurry S flowing through the return pipe 10 passes through the location where the discharge-side magnetic substance adsorbing means 4a is disposed, a foreign substance including a magnetic substance such as iron or a magnetic substance mixed in the raw material slurry S It is attracted and captured by the magnet of the ejection-side magnetic substance adsorbing means 4a, and the magnetic substance or a foreign substance containing the magnetic substance is prevented from flowing downstream. Since the supply side switching valve 6 is closed and the return side switching valve 5 is opened, the raw material slurry S that reaches the branching portion 11 flows through the return pipe 10. For this reason, it passes through the place where the return-side magnetic substance adsorbing means 4b is arranged, and the return-side magnetic substance adsorbing means 4b also adsorbs and captures the magnetic substance mixed in or the foreign substance containing the magnetic substance. Separated from the raw slurry S. The raw material slurry S flowing through the return pipe 10 is returned to the raw material tank 2 from the open end 10a, and is circulated between the raw material tank 2 and the circulation pump 3, and is subjected to the stirring action by the stirring device 8 in the raw material tank 2. The

  During the circulation, the raw material slurry S passes through the place where the magnetic substance adsorbing means 4a and 4b are arranged. Therefore, the foreign material containing the magnetic substance or the magnetic substance mixed every time it passes is separated, and the raw material slurry S It is prevented from flowing with. If the amount of the mixed magnetic substance or the foreign matter including the magnetic substance falls below an allowable value for use in the next process, the return side switching valve 5 is closed and supplied by circulating the appropriate number of times or the appropriate time. The side switching valve 6 is opened. Thereby, the raw material slurry S discharged from the circulation pump 3 is supplied after the foreign substance containing the magnetic substance or the magnetic substance is adsorbed and captured when passing through the place where the discharge-side magnetic substance adsorbing means 4a is arranged. It will flow through the tube 12. When passing through the place where the supply-side magnetic substance adsorbing means 7 is arranged in the middle of the flow of the supply pipe 12, the mixed magnetic substance or the foreign substance containing the magnetic substance is adsorbed, captured and separated. . This raw material slurry S is supplied to the next step such as the defibrating step 13. For example, the raw material slurry S supplied to the defibrating step 13 is supplied to a defibrating apparatus such as a high-pressure homogenizer and defibrated by receiving a mechanical shearing force.

As described above, since the supply side switching valve 6 is closed while the raw material slurry S is circulated through the return pipe 10, the raw material slurry S is supplied to the supply pipe 12 in the downstream portion of the supply side switching valve 6. Slurry S does not flow. For this reason, at the time of this circulation treatment, the magnetic substance or the foreign matter containing the magnetic substance captured can be removed by taking out the supply-side magnetic substance adsorbing means 7 from the supply pipe 12 and cleaning it. On the other hand, since the return side switching valve 5 is closed while the raw material slurry S is being supplied to the defibrating step 13, the raw material slurry S flows through the return pipe 10 downstream of the return side switching valve 5. Absent. For this reason, at the time of this supply process, the return side magnetic body adsorption | suction means 4b can be taken out from the return pipe | tube 10, and it can remove and remove the foreign material containing the magnetic body acquired by cleaning.
In this way, the pipes at the positions where the return-side magnetic substance adsorbing means 4b and the supply-side magnetic substance adsorbing means 7 can be taken out are detachable from the return pipe 10 and the supply pipe 12. That is, these magnetic substance adsorbing means 4b and 7 are disposed on the downstream side of the return side switching valve 5 and the downstream side of the supply side switching valve 6, respectively, so that they can be easily cleaned.

  Furthermore, since the circulation process for separating the magnetic substance or the foreign substance containing the magnetic substance from the raw material slurry S is a batch process, the raw material slurry S in the raw material tank 2 is emptied after being supplied to the defibrating process 13. The raw material slurry S to be processed is supplied to the raw material tank 2 that has become. Since the circulation pump 3 is stopped while the raw material slurry S is supplied, the raw material slurry S is not discharged from the circulation pump 3, and therefore, the discharge-side magnetic substance adsorbing means 4a can be taken out. Therefore, while the raw material slurry S is being supplied to the raw material tank 2, the discharge-side magnetic substance adsorbing means 4a can be taken out and cleaned. In addition, when installing a stop valve on the suction side or the discharge side of the circulation pump 3, the magnetic substance adsorbing means 4a, 4b, and 7 can be simultaneously cleaned by closing the stop valve.

  In the above description, the return side switching valve 5 is opened or closed and the supply side switching valve 6 is closed or opened. However, when the raw material slurry S is supplied to the defibrating step 13, for example, Both of the side switching valve 5 and the supply side switching valve 6 can be opened halfway so that a part of the raw slurry S is circulated and supplied to the defibrating step 13.

  In addition, a three-way valve can be provided at the branch portion 11, and the discharge side of the circulation pump 3 can be connected to either the return pipe 10 or the supply pipe 12. When a three-way valve is used, it is not necessary to arrange the return side switching valve 5 and the supply side switching valve 6.

  In the embodiment described above, the supply of the raw slurry S is performed using the circulation pump 3 both during the circulation process and during the supply process to the next process. However, the circulation pump used during the circulation process is used. A supply pump different from 3 may be connected to the raw material tank 2 and supplied to the defibrating process 13 by this supply pump.

  Furthermore, although the case where the magnetic substance or the foreign material containing the magnetic substance is separated in the previous stage of supplying the raw material slurry S to the defibrating step 13 is described, other steps, for example, the pulp dissolving step for generating the raw material slurry S Alternatively, the magnetic substance or the foreign matter containing the magnetic substance can be separated before or after the reaction process, the cleaning process of the generated raw slurry S, the dehydration process, or the like.

The result of confirming the effect when the magnetic material adsorbing means 4a, 4b, and 7 separated and separated the magnetic substance mixed in the raw material slurry S by the cellulose nanofiber manufacturing apparatus 1 and separated by the magnetic substance adsorbing means 4a, 4b, 7 2. The confirmation of the result was performed in the operable time of the defibrating apparatus used in the defibrating step 13. For comparison, data when the treatment for removing the magnetic substance or the foreign matter including the magnetic substance is not performed without using the cellulose nanofiber manufacturing apparatus 1 is also shown.
For the sample, a raw material slurry S diluted to 1 kg with a pulp having an absolute dry solid content of 10 kg to a concentration of 1% is added to the raw material tank 2, and the circulating pump 3 is operated while stirring with the stirring device 8. Circulation was performed so that the pipe 10 returned to the raw material tank 2. The circulation rate was 15 L / min.
A bar magnet having a surface magnetic flux density of 10,000 gauss or more was arranged in the pipe for the magnetic body adsorption means.

(Example 1)
The circulation process was performed for 120 minutes, and the magnetic substance adsorbing means 4a and 4b adsorbed and captured the foreign substance including the magnetic substance or the foreign substance containing the magnetic substance. These magnetic substance adsorbing means 4a and 4b were taken out, and the foreign matters adsorbed and captured were counted visually. At this time, those having a size of 0.2 mm ² or more shown in Annex JA “Visual Method Foreign Object Comparison Chart” in JISP 8145 “Paper and Paperboard—External Material Evaluation Method” were counted.
As a result, 1200 foreign objects were captured. When the raw material slurry S from which 1200 foreign substances were removed was supplied to a defibrating apparatus, continuous operation for 120 minutes could be performed.

(Example 2)
The magnetic substance adsorbing means 4a and 4b that have adsorbed the magnetic substance or the foreign substance containing the magnetic substance after performing the circulation process for 120 minutes are taken out to remove the trapped foreign substance and cleaned, and then attached to the return pipe 10, and the circulation process is performed again. For 120 minutes. When the magnetic substance adsorbing means 4a and 4b were taken out and the number of captured foreign matters was counted, 200 foreign matters were captured.
That is, it was circulated for 240 minutes to obtain a raw material slurry S from which a total of 1400 foreign substances were removed. When this raw material slurry S was subjected to a defibrating apparatus, continuous operation for 120 minutes or more could be performed.

(Example 3)
The magnetic substance adsorbing means 4a and 4b that have been circulated for 240 minutes to adsorb and trap the magnetic substance or the foreign substance containing the magnetic substance are taken out, removed and cleaned, and attached to the return pipe 10. The circulation treatment was performed again for 120 minutes. When the magnetic substance adsorbing means 4a and 4b were taken out and the number of captured foreign matters was counted, 50 foreign matters were captured.
That is, it was circulated for 360 minutes to obtain a raw material slurry S from which a total of 1450 foreign substances were removed. When this raw material slurry S was subjected to a defibrating apparatus, continuous operation for 120 minutes or more could be performed.

Comparative Examples 1 to 3 all show the case where the above-described sample was subjected to a defibrating apparatus without removing foreign matter, and as Comparative Example 1, clogging occurred in an operation time of 5 minutes. Stopped.
In Comparative Example 2, the operation was stopped in 15 minutes, and in Comparative Example 3, the operation was stopped in 2 minutes.

  That is, in the case of a sample, the defibrating device could hardly be operated in a state where the foreign matter was not removed, whereas the defibrating device was provided when the magnetic substance adsorbing means was disposed to remove the foreign matter. It was confirmed that it was possible to drive continuously with almost no hindrance.

  According to the cellulose nanofiber manufacturing method and manufacturing apparatus according to the present invention, the magnetic substance or the foreign matter containing the magnetic substance can be surely removed from the raw slurry, and the defibrating apparatus for the next step contributes to continuous operation without any trouble. Therefore, it is effective for improving the productivity of cellulose nanofibers.

DESCRIPTION OF SYMBOLS 1 Cellulose nanofiber manufacturing apparatus 2 Raw material tank 3 Circulation pump 4a Discharge side magnetic substance adsorption means 4b Return side magnetic substance adsorption means 5 Return side switching valve 6 Supply side switching valve 7 Supply side magnetic substance adsorption means 8 Stirrer 8a Stirring blade 8b Drive motor 8c Rotating shaft 9 Suction side pipe 10 Return pipe 11 Branching section 12 Supply pipe 13 Defibration process (next process)
14 Subsequent process S Raw material slurry

Claims (12)

In the method for producing cellulose nanofibers, a natural cellulose is used as a raw material to obtain a dispersion of cellulose fibers in which fine cellulose fibers are dispersed in a desired solvent.
Stirring the inside of the raw material tank where the raw material slurry of cellulose nanofiber is stored,
A circulation pump connected to the raw material tank returns the raw material slurry discharged from the raw material tank to the raw material tank through a return pipe connected to the discharge side of the circulation pump, and the circulation pump and the raw material tank Circulating the raw slurry between
Arranging a magnetic substance adsorbing means having a magnet in the middle of the return pipe to adsorb a magnetic substance or a foreign substance containing a magnetic substance mixed in the raw slurry,
A raw material slurry is circulated between the circulation pump and a raw material tank for a desired time, and then the raw material slurry is supplied to the next step.   The cellulose nanofiber according to claim 1, wherein a branch portion is provided in the middle of the return pipe to branch the supply pipe, and the raw material slurry is supplied to the next step through the supply pipe after circulation for a desired time. Manufacturing method.   The method for producing cellulose nanofibers according to claim 2, wherein a magnetic substance adsorbing means is disposed between the circulation pump and the branch part to adsorb the magnetic substance or a foreign substance containing the magnetic substance. A return side switching valve is arranged in the return pipe on the downstream side of the branch part,
The method for producing cellulose nanofiber according to claim 2 or 3, wherein a magnetic substance adsorbing means is disposed downstream of the return side switching valve to adsorb a magnetic substance or a foreign substance containing the magnetic substance. . A supply side switching valve is arranged in the supply pipe,
The cellulose nano according to any one of claims 2 to 4, wherein a magnetic substance adsorbing means is arranged downstream of the supply side switching valve to adsorb a magnetic substance or a foreign substance containing the magnetic substance. Fiber manufacturing method. In the cellulose nanofiber production apparatus for obtaining a cellulose fiber dispersion in which fine cellulose fibers are dispersed in a desired solvent using natural cellulose as a raw material,
A raw material tank for storing a raw material slurry of cellulose nanofibers;
A stirring device for stirring the raw material slurry in the raw material tank;
A raw material slurry circulation path including a circulation pump and a return pipe for discharging the raw material slurry from the raw material tank and returning it to the raw material tank;
A magnetic material adsorbing means having a magnet arranged in the middle of the raw material slurry circulation path,
While the raw material slurry is circulated between the raw material tank and the circulation pump through the raw material slurry circulation path, the magnetic material adsorbing means adsorbs the magnetic material or the foreign matter containing the magnetic material, and then supplies the raw material slurry to the next step. An apparatus for producing cellulose nanofibers, characterized in that:   The cellulose nanofiber according to claim 6, wherein a branch portion is provided in the middle of the return pipe to branch the supply pipe, and the raw material slurry is supplied to the next step through the supply pipe after circulation for a desired time. Manufacturing equipment.   The said magnetic body adsorption | suction means is distribute | arranged between the said circulation pump and the said branch part, The manufacturing apparatus of the cellulose nanofiber of Claim 7 characterized by the above-mentioned.   The cellulose nano according to claim 7 or 8, further comprising a pipe switching means for switching supply of the raw slurry discharged from the circulation pump to one or both of a return pipe and a supply pipe. Fiber manufacturing equipment.   10. The cellulose according to claim 9, wherein the pipeline switching means includes a return-side switching valve arranged in a return pipe downstream of the branch portion and a supply-side switching valve arranged in the supply pipe. Nanofiber manufacturing equipment.   10. The cellulose nanofiber manufacturing apparatus according to claim 9, wherein the pipeline switching means is a three-way valve disposed in the branch portion.   12. The magnetic material adsorbing means is disposed in one or both of a return pipe and a supply pipe on the downstream side of the pipe line switching means. Cellulose nanofiber production equipment.

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